While there is no official "portable" version of Clickteam Fusion 2.5 designed for thumb drives, users often create their own portable setups by following a few simple steps. This allows you to carry your game development projects and the engine itself between different Windows machines without a full re-installation. How to Make Clickteam Fusion 2.5 "Portable"
A portable installation on an external SSD performs nearly identically to a local install. Avoid cheap flash drives. Clickteam Fusion 2.5 portable